CHICAGO (MCT) — Investigations into the fatal Megabus accident earlier this month near Litchfield, Ill., and other recent high-speed crashes have prompted an emergency bulletin to motor coach companies nationwide about weight limits on tires when double-deck buses are fully loaded, officials said Thursday.

The bulletin issued by the Federal Motor Carrier Safety Administration cautioned motor coach companies to prevent tire failures by properly loading passengers and cargo and increasing pressure in tires on the rear wheels to the maximum marked on the tires when buses are carrying heavy loads.